The present invention relates to thermoplastic elastomer-adhesive laminates particularly useful for tire and other industrial rubber applications, and processes for producing such laminates.
When preparing dynamically vulcanized alloy (DVA) tire innerliners for assembly with a tire carcass, the thermoplastic elastomer may be co-extruded together with an adhesive tie gum layer. If the adhesive layer has poor cured adhesion to either the DVA or the tire carcass, the innerliner can delaminate within the tire. In the tire assembly process, temperatures are used that do not necessarily melt the DVA layer, i.e., once the film is formed in the coextrusion operation, the DVA may never become molten again. The known coextrusion operation imparts limited curing between the adhesive layer and the DVA such that the adhesive layer may be peeled relatively easily by hand from the DVA layer. Additionally, if the film wrinkles such that two adhesive surfaces touch, and the wrinkle is pulled apart after 3 hours, one side of the adhesive may delaminate from the DVA. On the other hand, if the adhesive layer is heated too long in the coextrusion process or at a temperature that is too high above its vulcanization temperature, the adhesive may scorch excessively, resulting in crosslinking, gel formation and/or degradation in the adhesive layer, and thereby reducing its efficacy in the tire. There is thus a need to improve the cured adhesion between coextruded DVA and an adhesive layer, without adversely impacting co-curability to a rubber substrate.